VolleyStringRequestToJSONObject

    private StringRequest stringRequest = new StringRequest(Request.Method.POST, url_register, new Response.Listener<String>() {
        @Override
        public void onResponse(String response) {
            String result = response.toString();
            textView.setText(result);
            Log.d("vol  ", "onResponse: "+result);

            ////////// CONVERT STRING TO JSON

            try {
                JSONObject stringJSON = new JSONObject(result);
                String code=stringJSON.getString("code");
                textView.setText(code);
            }catch (Exception e){}

        }
    }, new Response.ErrorListener() {
        @Override
        public void onErrorResponse(VolleyError error) {
            String eror = error.toString();
        }
    }){
        @Override
        protected Map<String, String> getParams() {
            Map<String, String> params = new HashMap<String, String>();
            String name = "";
            String email = "myemail@gmail.com";
            String passwd = "xyz321";
            params.put("name", name);
            params.put("email", email);
            params.put("passwd", passwd);
            return params;
        }
    };